51211220424 has 64 divisors (see below), whose sum is σ = 157572992640. Its totient is φ = 13506255360.

The previous prime is 51211220413. The next prime is 51211220449. The reversal of 51211220424 is 42402211215.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a junction number, because it is equal to n+sod(n) for n = 51211220394 and 51211220403.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11721997 + ... + 11726364.

It is an arithmetic number, because the mean of its divisors is an integer number (2462078010).

Almost surely, 2^51211220424 is an apocalyptic number.

It is an amenable number.

51211220424 is an abundant number, since it is smaller than the sum of its proper divisors (106361772216).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

51211220424 is a wasteful number, since it uses less digits than its factorization.

51211220424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23448390 (or 23448386 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 24.

Adding to 51211220424 its reverse (42402211215), we get a palindrome (93613431639).

The spelling of 51211220424 in words is "fifty-one billion, two hundred eleven million, two hundred twenty thousand, four hundred twenty-four".